Yea what Kani said..... A camo net, a rammer ,and the gun laying drive will be your best bet till you get your crew to 100% on concealment then you could switch out the net for a vent if you wanted to.

I just started arty just to do the missions and am trying all things mentioned above I did put liner on but really when you think about it if you are using a slow arty no point. Once the enemy sees you are dead really fast but if you have the M44 its is fast it can help you get out of the target zone quicker - found sometimes you make it other times you don't.

As for a third equipment, depends of your game style. I'm not a player that keeps the same spot, and considering the view range nerf of Patch 9.18 I opt to install the coated optics.
I don't recomend to install the camo net on arties that have a narrow traverse gun arc (like lots of the russians, for example), but I recomend to use it on the ones that are semi-turreted.
I strongly recomend to install Vents on the arties that can use it (like SU-14-2, 212A, M53/M55, for example).

what is the best way to configure arty for all around good performance, which equipment is good for arty is coated optics or binos even a choice

Rammer

Gun Laying Drive

(Vents if it's closed top, Bishop, FV304 and a few others)

Camo Net/Improved Suspension

Maybe improved Optics, but that really feels like a wasted slot.

Anything you can do to shorten: Load Time, Aim Time

and anything you can do to increase: Speed and Concealment

You are nearly wholly reliant on others to spot for you and it's really up to you to be aware of when you are about to be set upon by Red Team. If you are spotted and not ready to be spotted, then you die. Sometimes that happens even when you're ready, but you are responsible for your own defense and never rely on your team mates to come to your rescue. It does happen, but you should never count on it or expect it, they are usually just as busy as you are and more often than not, too far away to make a difference.

For those reasons, the only things I do to increase spotting distance is Recon and Situational Awareness (as there are not that many skills the RO can offer that are useful beyond Concealment, Repairs and SA for an SPG).

The Commander should always take Recon first (until you can reset it to 6th Sense, which I do after they are over 50% on their third skill). Presume you are always going to be spotted if you are out in the open and position yourself accordingly.

For faster SPGs the Optics might make a decent choice if you are going run around like an AMX or FV and running in TD mode. Binocs are a TOTAL WASTE of time and you'd be better off with a Camo Net, honestly.

You are nearly wholly reliant on others to spot for you and it's really up to you to be aware of when you are about to be set upon by Red Team. If you are spotted and not ready to be spotted, then you die. Sometimes that happens even when you're ready, but you are responsible for your own defense and never rely on your team mates to come to your rescue. It does happen, but you should never count on it or expect it, they are usually just as busy as you are and more often than not, too far away to make a difference.

For those reasons, the only things I do to increase spotting distance is Recon and Situational Awareness (as there are not that many skills the RO can offer that are useful beyond Concealment, Repairs and SA for an SPG).

The Commander should always take Recon first (until you can reset it to 6th Sense, which I do after they are over 50% on their third skill). Presume you are always going to be spotted if you are out in the open and position yourself accordingly.

For faster SPGs the Optics might make a decent choice if you are going run around like an AMX or FV and running in TD mode. Binocs are a TOTAL WASTE of time and you'd be better off with a Camo Net, honestly.

The open top/closed top is good advice, but a few SPGs are actually fine without the Gun Laying Drive. The 304 (Bert) is a good example. It actually works better with camo, vents and the rammer, because it needs to hide as its range is a laughably short 400-450 meters depending on the terrain and angle.

Other ones like the Russian bricks are so stupidly visible that you just want to aim and fire until you get shot.

Others that can be used like a makeshift TD, get the liner to take 2-3 hits to kill. ( the U.S. T18 is a prime example - fitted as a TD, it is a good TD as well as a SPG ) The most fun I had in a match this last month as a SPG was in my T18 watching 50 cal rounds bounce - 3 entire clips from a Luchs - as I slammed him in TD mode.

As an aside for arty set-up, I wonder why vents are not available for the tier X french arty. It is fully enclosed and should have vents as an available module. Other enclosed arty do e.g. Gun Conq, Battle Bus, 212A, and others.

Train BIA first, why waste crew xp to retrain later. I train cammo 2nd and then sixth sense on the commander as 3rd skill. I run food on all arties and have several of the bond gun laying drives on top arties. Move after every shot will cancel the need for a spall liner. Buy the food consumables when they are on sale at 50% off.

Also keep in mind certain crew skills compliment mounted equipment, AND/OR make up for a weakness. As a newer arty player, you will have unskilled crews, plain and simple. Understand how crew skills work; for each percentage gained, the next takes slightly more xp to earn it. This is the same for EACH SKILL too.

That means, the FIRST SKILL trains the FASTEST. This is why so many train Brothers In Arms PERK first. That added bonus sure helps all other learned and base skill. In an arty, clutch braking REALLY helps next skill on driver, especially in tank mode. It also helps AIM time just by being faster to rotate so reticle has more time to focus.